1. Field Of The Invention
The present invention relates to an apparatus and method for grasping an element for subsequent travel of said element, said element being carriable by a second element, such as a crane, or the like. In a preferred form, the apparatus is utilized within the bore of a longitudinally extending piling for use in a subterranean drilling platform.
2. Description Of The Prior Art
In the drilling of a subterranean offshore oil or gas well, it is, oftentimes necessary, to insert on the sea bed, a platform structure having a plurality of leg members extending above the water surface to the sea bed floor. At the top of the platform, the legs are connected by a series of "criss-cross" members, and at the immediate top of the legs, there is connected thereto a table-like member generally referred to simply as the "platform". From the platform, drilling operations are conducted, including the drilling of the well, the completion thereof, and workover operations. In some instances, the platform is utilized during production activities, such as setting and removing packers, gravel pack operations, testing programs, and the like.
Along the exterior of each of the legs of the platform structure are a series of longitudinally extending sleeve members which are welded or otherwise engaged to the platform legs, the sleeve members having bores therewithin for insertion therethrough of a piling member, which is subsequently and at least partially urged through the sea floor for securing the platform to the sea floor, or sea bed. Thereafter, the piling structure generally is cemented or "grouted" to the sleeve and, in turn, to the platform structure to assure proper engagement of the piling to the sleeve, and to assure the securing of the platform to the sea bed. Heretofore, the piling member has been inserted through the sleeve by means of a derrick or hoist apparatus, the holding line of which has been directly attached to the top of the piling by means of a welded cross-member or the like affixed thereto. Subsequent to the lowering operation, the wire line is retracted from the piling by mechanical means or, in some instances, it has been necessary to utilize a diver who will carry welding equipment which can be utilized in an aqueous environment to remove the cross member and the wire from the piling. These removal operations are extremely costly and time consuming.
With the present invention, it has been discovered that an apparatus can be provided whereby segmented units are urged outwardly and away from the apparatus to and within the base of the piling to grasp the piling interior. The apparatus is manipulated by a derrick or hoist line and can be readily and easily removed from the piling upon completion of the operation by activating the apparatus to cause the segmented elements to retract from the fixed position within the bore of the piling. Thereafter, the apparatus is removed from the piling to the top of the platform structure and may be reused for the setting of subsequently needed pilings.
The apparatus of the present invention may be used in conjunction with other elements which must be carried by a derrick, hoist or other apparatus, and is not necessarily limited for use in conjunction with pilings which are utilized with oil well drilling platforms. For example, the present invention could be utilized to carry tubing or pipe or other hollow members in the construction of buildings, pipelines, ships, and the like.